A perfect example of how this could be used would be for keymap help pages, giving examples of the most current keymaps in-line with the help guides. That way a user doesn't have to open pages from several different sites to follow one guide. There are other examples, such as making sure lists of certain parameters are always up to date, or just pulling some strings directly from the text on github.

You might ask, but why not just go to github for those things? Because on the wiki additional notes can be added :)

Especially for the end-user documentation.

I'll give one of these a try in the near future, and will be sure to post back if it works. Oh, and explain how to use these tags to embed github content onto wiki pages :)